Water-soluble polymers are well known for the retention or recovery of certain metal ions from solutions under certain conditions, e.g., certain pH conditions (see, e.g., Pure and Applied Chemistry. Vol. 52, pp. 1883-1905 (1980), Talanta, vol. 36, No. 8, pp. 861-863 (1989), and U.S. Pat. No. 4,741,831). Additionally, higher molecular weight varieties of the water-soluble polymers such as polyethyleneimine have been used as coatings on, e.g. silica gel, for separation and recovery of metal ions. However, the selectivity of the polymer for target metals due to competition from competing or interfering ions within solutions can present unique challenges.
It is an object of the present invention to provide novel water-soluble polymers.
It is a further object of the invention to provide compositions of water-soluble polymers having defined molecular weight ranges.
Still another object of the present invention is to provide compositions of water-soluble polymers including at least two different water-soluble polymers, the different water-soluble polymers differing in functionality, molecular weight range or both.